Autoregulation disturbance events correlate with history of loss of consciousness in mild traumatic brain injury patients

Abstract

Introduction: Cerebral autoregulation disturbance may compromise cerebral blood flow, thereby increasing the risk of hypoperfusion, which increases the risk of loss of consciousness (LOC). Transient hyperemic response test (THRT) using transcranial Doppler (TCD) can be used to assess cerebral autoregulation disturbance. The goal of this study was to assess the relationship between impaired cerebral autoregulation assessed using TCD and a history of LOC in patients with a mild head injury. Patients and Methods: This study was a comparative analytic study with unpaired data and cross-sectional design that involved 73 people divided into two groups. Group A (36 subjects) consists of mild brain injury patients with a history of LOC, and Group B (37 subjects) consists of mild brain injury patients without a history of LOC. THRT was assessed using TCD by identifying the absence (negative result) in flow velocity increase upon applying pressure on ipsilateral carotid artery. We employed the chi-square and logistic regression tests to assess any correlation between variables. A value of P < 0.05 was considered significant. Results: Approximately 93% of subjects who experienced LOC also showed negative THRT results. We found a statistically significant relationship (P < 0.001) between the history of LOC and THRT. In the logistic regression test, we found that age, gender, and hematocrit were not statistically related to negative THRT results. Conclusion: There is a statistically significant relationship between cerebral autoregulation disturbance and decreased consciousness event in mild head injury patients.